Improvement in slide-valve mechanisms



E. E. GILBERT. Slide-Valve Mechanisms-l No. 143,819,`Patelntedoct.21,1373.Y

' and thence to tubes D2.

` UNITED STATES.:

PA'IENT OFFIcE.

EBENEZEB E. GILBERT, OF MONTREAL, CANADA.

IMPROVEMENT IN SLIDE-VALVE MECHANISMS.

Specication forming part of Letters Patent No. 143,819, dated October21, 1873; application led May 10, 1873.

To all whom it may concern:

, Be it known that I, EEENEZER E. GILBERT,

l my improved valve mechanism attached.

The invention consists in the improvement of valve mechanism forsteamengines, as hereinafter described, and pointed out in the claim.

A represents a steam-cylinder, having a piston, B, steam inlet andoutlet ports m fm', and exhaust W. C is the main slide-valve, which hasend tubes D2 that slide upon the close-tting guide-rods D1 Dl. Theseguiderods have rear iianges, d, that hold them movably between4guide-brackets b. When the friction between the valve C and its seatcreates wear, the valve is thus enabled to lower itself andautomatically take up the wear.

As the reciprocation of the valve upon its guide-rods is liable to beattended with a clap` ping and disagreeable noise, it has been quite Yan object to prevent this, if possible.

I have accomplished this object by the use of an auxiliary valve, E,peculiarly constructed, and ar- -ranged in the steam-chest p and overthe main valve. This valve E has two subjacent cavities, e e, whichalternately connect with the exhaust W by a vertical passage, g, and areseparated by a partition, c1. ff are the ports, through which steampasses into and out of the tubes D2, to alternately force the main valveC in opposite directions, while ff' are recesses, over which pass thcends of the valve E, to admit steam into chambers el e, My object is tocut oi the egress of steam from these cylinders in time to form acushion, to prevent their percussive impact upon the rods D1. For thatpurpose the exhaust-passage gis s o locally arit with two upwardprojections, e2 e2, between which works loosely a free end of thecrankarm Vh of the rock-shaft K, which is connected by a pitman, k, tothe reciprocating rod of the piston B. By this means the auxiliary valvebecomes automatically adjustable by its own gravity, both as respectsits own wear and that of the main valve.

My novel mode of constructing and arranging my auxiliary valve upon themain one embodies the following jlhode of operation: As shown in Fig. lof the drawing, the valve E has begun to admit steam to the chamber e;but just before this has occurred the partition e1 has covered thepassage g, thus cutting o the escape of a portionzof the steam in tubeD2, and forming a cushion against the rod D1. p

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination, with main valve C, having end tubes D2, ofguide-rods D1, having iianges d arranged loosely in brackets b, as

and for the purpose described.y

2. The auxiliary slide valve E, having the subjacent cavities e e andvpartition e1, combined with the main slide-valve C, having passage g,end recesses f f', and tubes D2 with passages f, as and for the purposeset forth. EBENEZER EDWIN GILBERT.

Witnesses:

GEORG-E O. MoFFAT'r, VJOHN G. GRIFFIN.

